Well if u buy seawater u put live bacteria in your tank and that make the different no question about that. But if u put mix salt u not going get the live bacteria u really need , my tank never going get crash , but if u use mix salt u need keep in your mind u have 50%by50% this happend with all coral people buy , they thing is light is not , and you can have many fish u want the long u keep do water change with the seawater , animal planet have the show (tank) the guy only use nutriseawater come number one from EUA , believe me that make different natural water , just give shot and u will see in two days , about color grown 60% more than mix salt